Modular breathing mask



FIG. 1 is a perspective view of a modular breathing mask according to a first embodiment of the present invention;

FIG. 2 is a rear view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is an exploded view thereof. 

The ornamental design for a modular breathing mask, as shown and described. 